A woman was arrested yesterday for setting fire to a flat in Mong Kok by burning clothes. The fire broke out at about 11am in the flat on the 18th floor of the Yuen Fat Building in Nelson Street. A source at the scene said the woman had moved into the rented apartment just two days ago. A police spokesman said a witness in a building across the road saw smoke pouring from the flat and reported the case to police. Firefighters put out the blaze in 20 minutes and found the case to be suspicious. No injuries were reported. 'As police officers were investigating the case, officers found the arrested person on a staircase of the building and she admitted she had burned clothes, as she was not happy,' the police spokesman said. The woman was escorted to a police van by female officers. Thick smoke poured from the flat, and windows were destroyed by the fire. An air conditioner fell onto the 8th-floor podium, after a support frame was damaged by the blaze. Some residents sought fresh air on the building's rooftop, while others followed police and firefighters' instructions and left the building. A member of the building's owners' corporation committee said at the scene that the woman had admitted setting fire to the flat when speaking to a security guard on a staircase. 'The security guard tried to put out the fire with an extinguisher and met the woman on the 13th floor on the staircase. The guard asked her what happened and she admitted that she set fire to the unit,' he said.